Brush mounting arrangement



pril 11 BRUSH MOUNTING ARRANGEMF uNT Filed Jan. 6, 1964 W I M,

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I INVENTOR.

United States Patent Ofitice 3,3133% Patented Apr. 11, 1955'? The present invention relates to a brush mounting arrangement fora rotary electric machine, and more particularly to a brush holder for a direct current motor.

It is the principal object of the present invention to mount a brush on the housing of an electric machine in such a manner that the brush is easily accessible, and can be exchanged or adjusted in an easy operation requiring only little time.

Anotier object of the invention is to provide a brush holder which can be attached to the housing of an electric motor and detachedtherefrom, without tools.

Another object of the invention is to provide a brush mounting arrangement which is covered by the housing of the machine so that it is not subjected to dust deposits, and is protected from accidental damage.

With these objects in view, one embodiment of the invention comprises a brush holder having a plurality of attaching elements, such as prongs for detachably attaching the holder to a wall of the housing of an eiectric machine, such as a rotor. The brush holder has a channel-shaped guide way and is attached to the wall of the housing in such a manner that the wall closes the open side of the channel-shaped guide way. A brush is mounted in the guide way and is urged by a spring out of one end of the guide way and toward the commutator.

In the preferred embodiment of the invention, the holder has a U-shaped cross section and pairs of prongs project from the edges of the lateral walls of the brush holder. The prongs pass through corresponding slots in the supporting housing wall, and are bent over on the other side of the Wall. Thus, the attachment or removal of the holder requires only the bending of the prong-s, and no tool is needed.

Two supporting walls project transversely to the main axis of the housing into the interior of the housing substantially parallel to the transverse end members of the housing in which the bearings of the rotor are located. The respective end member has two large cutouts, closed by cover plates which upon removal permit access to the brush holder when the detachment or repair is necessary.

The novel features which are considered as char-acteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method or" operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

PEG. 1 is a sectional view taken on line 1-1 in FIG. 2, and illustrating an electric motor provided with a brush mounting arrangement according to one embodiment of the invention;

FIG. 2 is an end view of the embodiment of FIG. 1, with a portion of the endmember of the housing omitted for the sake of clarity;

FIG. 3 is a' fragmentary perspective View illustrating the brush holder of the embodiment of FIG. 1;

FIG. 4 is a fragmentary perspective View illustrating a detail of the embodiment of FIG. 1;

FIG. 5 is a sectional view taken on the line V-V in FIG. 6 and illustrating another embodiment of the invention;

FIG. 6 is an end view of the embodiment of FIG. 5 with a portion of the end member of the housing omitted for the sake of clarity; and

FIG. 7 is a perspective, partly exploded View illu'strating the parts of the embodiment of FIG. 5.

Referring now to the drawings, and more particularly to FIGS. 1 to -4, an, electric motor includes two housing parts 1 and 1 connected to each other by two bolts 21 which are arranged diametrically to each other in housing part 1 and have threaded ends projecting into prismatic nuts in located in corresponding recesses of housing part 1. A laminated iron core 15 providing pole shoes, as best seen in FIG. 4, supports a stator winding 12. A rotor is mounted within the stator and has a commutator 2, and a shaft 13, portions of which project from the rotor and are located in bearings 23 provided on the end members of the housing-parts 1 and 1'. A fan 13a and a pulley 1-8 are secured to one shaft portion.

As best seen in FIG. 2, the end member of the housing part 1 is provided with two large cutouts 16a in which cover plates 16 are mounted. Only one cover plate 16 is shown in FIG. 2. Cover plates 1-6 are held in place by screws 22 threaded into the prismatic nuts 1a. Each cover plate 16 has at the outer end thereof a flange 16a fitting into a corresponding recess in housing part 1, and the main portion of each cover plate 16 rests with its inner face on a corresponding shoulder provided on the end member of housing part 1 along the three edges of the cover plate 16.

Two supporting walls 8 project inwardly from housing part 1 into the interior of the housing and substantially parallel to the housing end members and cover plates 16. As best seen in FIG. 2, the shape and location of walls 8 corresponds to the shape of cover plates 16, so that walls 8 are accessible when the respective cover plates 16 are removed.

Each wall 8 has two pairs of openings or slots 9 arranged in the pattern of slots 39 in FIG. 7 which illustrates another embodiment of the invention.

A brush holder 5 of U-shaped cross section has lateral walls from whose edges two pairs of rectangular prongs 7 project. The shape of the brush holder 5 corresponds to the shape of brush holder 35 illustrated in FIG. 7.

The prongs 7 of the brush holder are inserted into the corresponding openings 9 in support wall 8, and bent over on the other side of wall 8. In this manner, the brush holder is tightly and non-turniably, but detachably secured to the housing of the motor. The U-shaped brush holder 5 defines a channel-shaped guide way Whose open side is closed by wall 8 when the brush holder is attached to the same.

A brush 3 is mounted in the guide way for longitudinal movement and is urged by a spring 4 toward the commutator 2 of the motor.

The construct-ion of the upper end of brush holder 5 is best seen in FIG. 3. The outer end of brush holder 5 has a flared end portion 6 on which a matching cap 10 is mounted. Cap 10 is springy and has-a somewhat trapezoidal outline so that the lateral parts of cap 10 snap onto the flaring end portion 6 and are resiliently held thereon. A connector 11 is soldered or otherwise secured to a projection of the band-shaped cap member 10 and connects the same with the stator winding, as best seen in FIG. 2.

Referring now to FIGS. 5 to 7, the general arrangement is the same as described with reference to FIGS.

member 46 rests.

1 to 4, and a motor housing 31 is provided with a laminated iron core 45 and stator windings 42 which surround a rotor including a commutator 32 and a shaft 43 on which a pulley 48 is mounted. Bearings 53 support rotor shaft 43. The housing parts are held together by bolts 51 engaging prismatic nuts located in corresponding recesses of the housing.

The end member of the housing on the commutator side is provided with a detachable cover plate 45 which has parallel edges 46a, transverse edges 46b on curved and bent over flange portions 46d, and a central opening bounded'by an edge 46c, and receiving the bearing shell of bearing 53 which forms part of a depressed portion 31a of theend member ofthe housing on which the cover sides of the depressed portion 31a of the end member have outer surfaces flush with the outer surface of cover members 46. Cover member 46 is secured by a screw 52 1 toward the commutator 32. Spring 34 abuts a cap member 40 provided with prongs 55 which are also inserted into the upper pair of slots 39. Cap 40 is seated on the end portion of holder 35 so that prongs 55 and the upper pair of prongs 37 are located superimposed on each other and can be simultaneously inserted into the pair of slots 39in wall 38. A conductor 41 connects the stator winding with the brush or the brush holder, and the end of conductor 41 may be soldered to the lateral wall of brush holder 35, or to cap member 40.

In contrast to the arrangement of the embodiment of FIG. 1 in which the cap was resiliently held on the brush holder, the embodiment of FIGS. 5 to 7 provides a more rigid support of the cap 40. In both constructions, the caps form abutments for the outer ends of the springs which urge the brushes against the commutator.

As best seen in FIG. 7, housing part 31 has a curved recessed portion 31s on which a corresponding curved portion 46d of the cover plate is located. An insulating means 36 is located between cap 40 and curved flange portion 46d of cover plate 46. In the region of the brush holders, a full cutout 31 is provided so that upon removal of the cover plate, the brush holder is completely accessible.

In both embodiments of the invention, the cover plates are removed by loosening and removing the respective screws, whereupon the brush holder or holders are accessible to the operator who can remove the brush holders and caps by bending the prongs to the straight position shown in FIG. 7. After replacement of the brush, the prongs are again inserted into the corresponding slots and bent over on the other sides of the support walls. In the embodiment of FIGS.'5 to 7, the upper prongs 37 of brush holder 35 are bent inwardly toward each other, and prongs 55 of cap 40 which are located outwardly of prongs 37 in the same slot 39, are bent outwardly.

Due to-the permanent and fixed arrangement of the support walls with the supporting slots 9 and 39, the brush holders and brushes will be always in exactly the same position relative to the commutator although the brush holders can be easily detached for the purpose of exchanging, cleaning or inspecting the brushes.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of brush mounting arrangements for rotary electric machines differing from the types described above.

The lateral portions 3112 on opposite While the invention has been illustrated and described Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended Within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. Brush mounting arrangement for a rotary electric machine, comprising, in combination, housing means including a wall having a plurality of openings; brush holder means including a holder having a U-shaped cross section forming a channel-shaped guide way closed by said wall, said holder having lateral portions including rectangular plates having edges abutting said wall and attaching prongs projecting from said edges, said prongs projecting through said openings fro-m one side of said wall to the other side and being bent over on said other side for detachably attaching said holder to said wall; a brush movably mounted in said guide way projecting from one end of said holder; a cap member mounted on the other end of said holder and forming an abutment in said guide way, said cap member having a plurality of prongs projecting through corresponding openings in said wall from one side to the other side of the same and being bent over on said other side; and spring means disposed in said guide way abutting said brush and said cap member.

2. Brush mounting arrangement for a rotary electric machine, comprising, in combination, housing means including a wall having a plurality of openings; brush holder means including a holder having a U-shaped cross section forming a channel-shaped guide way closed by said wall, said holder having lateral portions including rectangular plates having edges abutting said wall and attaching prongs projecting from said edges, said prongs projecting through said openings from one side of said wall to the other side and being bent over on said other side in one direction for detachably attaching said holder to said wall; a brush movably mounted in said guide way projecting from one end of said holder; a cap member mounted on the other end of said holder and forming an abutment in said guide way, said cap member having a plurality of prongs projecting through corresponding openings of said openings in said wall from one side to the other side of the same and being bent over on said other side in the opposite direction; and spring means disposed in said guide 'way abutting said brush and said cap member.

3. An arrangement as set forth in claim 2 wherein said cap member has two outwardly bent prongs passing through two of said openings, and wherein two of said prongs of said holding means pass through the same openings and are inwardly bent.

4. Brush mounting arrangement for a rotary electric machine, comprising, in combination, housing means having an end member formed with at least one opening, and support wall means located inwardly of said end member and opposite of said opening, said support wall having a plurality of slots; brush holder means including a holder having a U-shaped cross section and forming a channel-shaped guide way closed by said support wall, said holder having lateral walls having edges abutting the outside of said support wall, and attaching prongs projecting from said edges through said slots and being bent over on the inside of said support wall for detachably attaching said holder to the outside of said support Wall opposite said opening, and a cap member on said holder closing said guide way and having a pair of prongs projecting through said slots and being bent over on the inside of said support Wall for detachably attaching said cap member; and at least one cover member located outwardly of said end member and closing said opening, said cover member being detachably attached to said housing means so that said support Wall means and said brush holder means are accessible through said opening in said end member upon removal of said cover member whereby said brush holder can be detached and removed.

References Cited by the Examiner UNITED STATES PATENTS Happe 310-247 Luther et a1. 310-247 Hansen et a1 310-239 Baumhart 310-239 Apostoleris 310-239 Gardner 310-239 10 MILTON o. HIRSHFIELD, Primary Examiner.

D. F. DUGGAN, Assistant Examiner. 

4. BRUSH MOUNTING ARRANGEMENT FOR A ROTARY ELECTRIC MACHINE, COMPRISING, IN COMBINATION, HOUSING MEANS HAVING AN END MEMBER FORMED WITH AT LEAST ONE OPENING, AND SUPPORT WALL MEANS LOCATED INWARDLY OF SAID END MEMBER AND OPPOSITE OF SAID OPENING, SAID SUPPORT WALL HAVING A PLURALITY OF SLOTS; BRUSH HOLDER MEANS INCLUDING A HOLDER HAVING A U-SHAPED CROSS SECTION AND FORMING A CHANNEL-SHAPED GUIDE WAY CLOSED BY SAID SUPPORT WALL, SAID HOLDER HAVING LATERAL WALLS HAVING EDGES ABUTTING THE OUTSIDE OF SAID SUPPORT WALL, AND ATTACHING PRONGS PROJECTING FROM SAID EDGES THROUGH SAID SLOTS AND BEING BENT OVER ON THE INSIDE OF SAID SUPPORT WALL FOR DETACHABLY ATTACHING SAID HOLDER TO THE OUTSIDE OF SAID SUPPORT WALL OPPOSITE SAID OPENING, AND A CAP MEMBER ON SAID HOLDER CLOSING SAID GUIDE WAY AND HAVING A PAIR OF PRONGS PROJECTING THROUGH SAID SLOTS AND BEING BENT OVER ON THE INSIDE OF SAID SUPPORT WALL FOR DETACHABLY ATTACHING SAID CAP MEMBER; AND AT LEAST ONE COVER MEMBER LOCATED OUTWARDLY OF SAID END MEMBER AND CLOSING SAID OPENING, SAID COVER MEMBER BEING DETACHABLY ATTACHED TO SAID HOUSING MEANS SO THAT SAID SUPPORT WALL MEANS AND SAID BRUSH HOLDER MEANS ARE ACCESSIBLE THROUGH SAID OPENING IN SAID END MEMBER UPON REMOVAL OF SAID COVER MEMBER WHEREBY SAID BRUSH HOLDER CAN BE DETACHED AND REMOVED. 